With the development of integrated circuits, programmable logic devices such as Field-Programmable Gate Array (FPGA) have been increasingly applied to various fields. Since the FPGA is a programmable logic device, users can design their own data stream files and store them in internal memory of the FPGA to enable the FPGA to perform the corresponding functions. For the FPGA, the internal memory thereof is generally a nonvolatile memory. The data in the nonvolatile memory is not lost after the power is turned off, which will give the criminals a chance to remove the FPGA device directly from the system board to study the way of crack and then read out the data in the FPGA.
In order to solve the above problem, the currently existing technologies mainly make the data unreadable by setting one or more security bits. However, although the above method can encrypt the data, the device is readable in a default state, that would make the criminals to find the security bit in the device through a cracking technology. On the basis of finding the security bit, as long as the security bit is damaged, the criminals make the device enter a readable state, and read the data in the device. What's more, when only one security bit is set, or the security bits are relatively centralized, it is possible to erase just the security bit by a precise positioning erasure. This makes it easy to crack the data and greatly reduce the security of data storage.
Therefore, it is necessary to provide a technical solution to solve the technical problems mentioned above.